Is There a Preferred Surgical Technique for Management of Pyriform Sinus Branchial Anomalies?

Pyriform fossa sinus tracts (PFSTs) are rare congenital anomalies arising from an abnormal connection between the pyriform sinus and neck. These lesions typically present in early childhood as recurrent neck abscesses or suppurative thyroiditis, and are predominantly left-sided in nature. Diagnosis is confirmed with direct visualization of the pyriform sinus opening. Conventional definitive treatment consists of surgical sinus tract excision with or without hemithyroidectomy. More recently, there is a growing interest in primarily managing PFSTs with endoscopic therapies to ablate the tract opening, avoiding the need for an open procedure altogether. PFSTs comprise 3%–10% of branchial pouch malformations and their embryologic origin has been debated [1]. They are also known as third or fourth branchial anomalies, but more recently it has been suggested that they result from failure of the thymopharyngeal duct to obliterate [2]. Differentiation between third and fourth branchial anomalies can only be made by tracing out the anatomical course surgically but is ultimately inconsequential from a clinical perspective. PFSTs typically present as recurrent lower midline neck abscesses or suppurative thyroiditis, but can also present with airway compressive symptoms, particularly in the neonate. Initial imaging can include an ultrasound (US), computed tomography (CT), or magnetic resonance imaging (MRI) demonstrating a tract extending from the pyriform sinus to the neck, in association with the thyroid gland and inflammatory changes if acute infection is present. Other imaging modalities include barium swallow to reveal the sinus tract. Visualization of the sinus opening in the pyriform sinus on laryngoscopy confirms the diagnosis. When an abscess is present, incision and drainage (I&D) is a reasonable initial treatment option but has a high rate of failure (89%–94%) [3]. Therefore, complete surgical excision of the sinus tract, performed several weeks after acute infection has resolved, has historically been regarded as definitive management. Thyroid lobectomy is also performed concurrently if there is involvement of the thyroid gland, typically seen in the left superior thyroid lobe. Success rates, defined as no recurrence of symptoms or infection, are high. A study by James et al. reported a 100% success rate for 17 patients, although 14 of those patients had previously undergone either I&D or prior excision [1]. Another systematic review by Nicoucar et al. reported a 95% success rate for patients treated with primary surgical excision [4]. Open surgery is commonly utilized in cases of failure of I&D and endoscopic intervention [4, 5]. Complications of surgical excision included permanent or transient vocal fold paralysis or paresis, salivary fistulas, and recurrent infection, reported in 6% of patients and noted to be higher in children less than 8 years of age [2, 4]. Endoscopic cauterization of the pyriform sinus tract opening was first described in 1998 and since then, various endoscopic therapies have been introduced [2]. A systematic review by Lachance et al. that included 84 pediatric patients across 13 studies treated endoscopically for PFST found that electrocautery was the most commonly used (39/46.4%) followed by laser (19/22.6%), trichloroacetic acid (19/22.6%), silver nitrate (4/4.8%), combination of silver nitrate and laser (2/2.4%) and fibrin glue (1/1.2%) [2]. While electrocautery is the most commonly reported treatment option in some studies, others have reported a large number of patients treated with chemocautery [3, 5]. The overall success rate for endoscopic management of PFST is 89.3%, with slightly higher success in primary cases compared to revision cases (90.5% vs. 85.7%, respectively) [2]. Notably, there have been reports of patients successfully treated endoscopically following unsuccessful open excision [5]. Overall, there was a 2.4% complication rate for endoscopic interventions, namely temporary vocal fold immobility with TCA, thought to be related to inflammation and localized edema resulting in compression of the superior or recurrent laryngeal nerve [2]. The open and endoscopic approaches have similar rates of success. A systematic review by Derks et al. found a cumulative success rate of 50%–100% for open surgery after the first treatment and 100% for the second treatment. The cumulative success rate of endoscopy with electrocautery after the first treatment was 66.7%–100% and 77.8%–100% after the second treatment. Other endoscopic treatments could not be compared to open intervention owing to small cohort sizes, but meta-analysis comparing the success of electrocautery to surgery as definitive treatment demonstrated no differences in preventing recurrence. Importantly, all included studies, with the exception of one, advocated for endoscopy with cauterization as a first-line treatment, with open intervention reserved for refractory cases [3]. Another systematic review found a recurrence rate of 14%–15% for surgical excision with or without thyroid lobectomy compared to 18% for endoscopic cauterization. The authors' proposed treatment algorithm suggested endoscopic intervention was reasonable for those younger than 8 and surgical excision for those older than 8, given the higher rate of complications observed in the younger cohort [4]. There are several limitations regarding the management of PFSTs. All available studies are retrospective in nature. The inherent rarity of PFSTs further complicates the ability to conduct prospective analyses. Notably, the reported success rates for open excision combine procedures with and without thyroid lobectomy, which may be distorting the true success rate for comprehensive open treatment with thyroid lobectomy. Additionally, there is significant variability in endoscopic treatment modalities, making it difficult to perform statistical analysis and draw meaningful conclusions. Available data also differ considerably in reported outcomes and long-term follow-up. Given the limitations of the rarity of PFSTs and no prospective studies, the current literature supports endoscopic treatment of PFSTs as a viable initial treatment option when compared to traditional surgical excision. Pyriform fossa sinus tracts are rare entities that typically present with recurrent lower neck abscesses or suppurative thyroiditis. Although they have been traditionally managed with open surgical excision of the entire tract, based on current evidence, endoscopic cauterization of the sinus tract opening in conjunction with I&D appears to be a safe, less invasive treatment option with similar success rates to open intervention as a first-line treatment. In patients with recurrent infections or abscesses, additional endoscopic interventions may be necessary. Given lower morbidity, it is reasonable to initially treat with endoscopic intervention. Excision of the sinus tract with thyroid lobectomy should be considered if there are concerns about a patient's ability to access longitudinal care or for those who continue to have recurrent neck abscesses. Current quality of evidence is modest due to the retrospective nature of studies and small cohorts. This work cites level 4 studies. Prospective studies would be beneficial but are difficult given the low prevalence of this condition. The authors declare no conflicts of interest. The data that supports the findings of this study are available within the cited references of this article.